Carl, I've had the truck a number of years but never got around to its restoration. That is now nearly done. The individual i purchased it from was using it as a daily driver. Don't know much beyond that. As far as I know everything was original (a few minor exceptions). Don't really know how I would determine if the backing plate or rear axle was ever replaced. As far as the brakes go everything is original with the exception of the brake shoes and wheel cylinder (unfortunately I threw the originals out prematurely). I did purchase a new drum just to see what the actual ID of a new drum was. The replacement shoes and cylinder came from Classic Parts. I called them today to see if they could help or had any ideas. They said they have never encountered this problem and provided no help. I will check the bottom pivot pin and bolts location with Andy as we have been using his 48 or 49 (i forget which) as a reference since his brake geometry seems to be just fine.